EDIT: I found that the peg that connects to the sender wire to the circuit board was not giving a good connection. I tried moving it which broke it off. After soldering it back on I have a good connection. Now when I turn the ignition key the gas gauge pegs to full. Could this be a bad ground on the sender?

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I'm having trouble getting my gas gauge to work on my 64 dart.

It never has worked since I bought the car about two months ago. The temp gauge and ammeter are working. A couple of weeks ago I grounded the sending wire with my wife watching the gauge and she said that slowly went to full after a few seconds. I ended up pulling the sending unit and saw that I had a bad float, so I replaced with a new sending unit from vans. After I put everything back together I fully expected the gas gauge to work and it still sat on empty.

I then tried the ground test and the gauge did not move. I checked the resistance on the sending unit and was able to get a good reading indicating that it was working correctly. Thinking I did something to mess up my gauge I purchased another one and tried it out with no luck. Only with the replacement gauge the temp gauge started to go all the way over when I turned on the car.

I tried a third gauge with the same result as my original gauge. It also did not move when I grounded the sending wire.

I've tested a couple of the gauges voltage regulator by connecting them to my battery (Positive to I on gauge and Negative to ground on gauge) and read the voltage at the I terminal and on the S terminal. The I terminal read 12.4 volts and the S terminal voltage bounced between 0 and 7-11 volts. My service manual said that the voltage on the S terminal should only bounce between 0-7.

Anyway, I'll be out working on the car tomorrow to see if I can figure anything else out, so and advice would be much appreciated!

Thanks,
Robert

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64 Dart GT - 225

Have you grounded the sending unit?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I believe so. I put back on the grounding strap.

Is there a way to bench test the gauge? I've also thought of trying to remove the gauge and take voltage readings on the circuit board. I may try that tomorrow.

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64 Dart GT - 225

Make sure your ground connections are clean. Sounds like a possible grounding issue.

I was getting really annoyed by reading your problem. I can't even imagine having to actually deal with that. Why do 2 things always break at once? What a pain

Thanks for the advice! I may recheck my ground strap on the sending unit again. If the sending unit is not properly grounded would that cause the pegged gas gauge? As far as other ground connections, are there others that would be involved with the gas gauge?

It's not all bad...at least I'm getting pretty good at removing the dash

I guess these sort of problems are bound to happen with a 45 year old car.

Thanks again!
Robert

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64 Dart GT - 225

If the gas gauge (tank) is not grounded, the gauge will read low or E, not F - if the dash or gauge is not grounded, the gauge could peg. You ought to see pulsing 12V at the sender - steady 12V means no ground or a shot limited. I'm pretty sure the limiter is inside the '64's gauge, but I can't swear to it.

Thanks, that helps! I'm thinking now that I didn't have my cluster secured to the dash (no ground) when I tested the last time. That would explain the 'Full' reading. And yes, the '64's have the internal limiter. I plan on doing the RTE external limiter soon.

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64 Dart GT - 225

Another update...I was able to get the gauge working. I inadvertently broke off the pin for the sending unit on the circuit board. After trying to solder it back on with poor results I ended up running a jumper wire from the sending unit wire to the back of the gauge.

Thanks everyone for the help!

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64 Dart GT - 225

A six volt lantern battery across hot peg and ground peg will
show half tank if gauge is good.

shadetree

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brass handled wrench,bfh and a BIG screw
driver. If it aint drawn blood you aint done.